Traveling nearly 1,600 miles from Galveston, investigators arrived in Philadelphia Sunday with mixed emotions.
"I'm glad we got him, but it's kind of sad what he did to the child," said Sgt. Annie Almendarez with the Galveston Police Department.
In her 13 years as an officer, Sgt. Almendarez has investigated her share of violent crime. As a parent, the case of 3-month-old Alijah Mullis is one of the hardest.
"I have two boys at home and when I read the statement, it brought tears to my eyes," she said "But I have a job to do and I'm going to do it to the best of my ability."
Police say 21-year-old Travis Mullis confessed to killing his son by stomping on his head several times. Galveston authorities have been looking for him since Tuesday, when sightseers discovered the baby's body on the side of the road by the Seawall.
Mullis made his way to Pennsylvania, where he surrendered to Philadelphia police Friday afternoon.
Galveston homicide detectives are expected to come face to face with Mullis for the first time behind the gates of a holding facility. He was transferred there after turning himself into police.
Meanwhile, Mullis is undergoing a mental and physical evaluation and will likely be housed by himself in protective custody, waiting for Galveston investigators to question him.
Galveston police are going to meet with Philadelphia police Monday morning. Mullis is being held without bail. His extradition hearing is scheduled for February 11.